Centrifuge apparatus with flexible boot



Dec. 23, 1969 LQ Q NGEL '3',:4s5,445

CENTRIFUGE APPARATUS WITH FLEXIBLE BOOT A Filed May 22, 1968 2 Sheets-Sheet 1 \QJly 5 LEWIS o. ENGEL BY 6 wwmz ATTORNEYS L. O. ENGEL CE'NTRIFUGE APPARATUS WITH FLEXIBLE BOOT Dec. 23, 1-969 2 Sheets-Sheet '2 Filed May 22, 1968 INVENTOR LEWIS O. ENGEL @Zwm / ATTORNEYS United States Patent f 3,485,445 CENTRIFUGE APPARATUS WITH FLEXIBLE BOOT Lewis 0. Engel, 39428 Cloverleaf Drive, Mount Clemens, Mich. 48043 Filed May 22, 1968, Ser. No. 731,244 Int. Cl. B04h 15/.06 US. Cl. 233--28 Claims ABSTRACT OF THE DISCLOSURE Centrifuge apparatus in which an open-ended, compartmented, expansible boot is mounted on an open end rotor so that the boot will clean itself automatically of sludge, prevent the flow through of contaminated fluid until sufficient centrifugal force is present to effect desired clarity, and provide rotational balance of rotor and boot. The boot expands and contracts as the pull of centrifugal force increases or decreases due to variations of the rotational speed of the rotor to thereby accomplish the desired separation of sludge from the fluid fed to the boot.

BACKGROUND OF THE INVENTION There is a great desire for inexpensive apparatus capable of reclaiming fluids used in various equipment. Such apparatus must be capable of separating foreign substances from the fluid, for example, removing sludge from dirty fluid which it is desired to reuse.

It is an object of this invention, therefore, to provide an improved centrifuge apparatus in which a flexible boot operates to achieve this desired separation.

SUMMARY OF THE INVENTION In the apparatus of this invention an open-ended rotor is provided having a radially inwardly concave portion which extends about its axis of rotation. A flexible boot is mounted on the rotor so that it extends across the concave portion when the rotor is at rest. The boot has compartments into which fluid to be cleaned is fed, and the boot is flexible enough to provide for its movement into the concave rotor portion during rotation of the rotor. As the compartments in the boot receive fluid, the fluid passes through the compartments and is recirculated through the compartments or pumped out of the apparatus until a desired centrifugal force is applied to the boot. When this desired centrifugal force is applied to the boot, the boot flexes into the concave rotor portion. The heavier foreign particles in the fluid are thrown radially outwardly by centrifugal force so that they accumulate on the radially outer sides of the compartments. The pressure of the fluid created by centrifugal force on the column of incoming contaminated fluid forces the lighter, and thus clean, fluid to the radially inner side of the compartments from which it flows through openings in the boot disposed on the radially inner sides of the compartments. Passages extend through the boot and the rotor for radially outward flow of this clean fluid into the housing surrounding the rotor. The clean fluid is then readily removed through an outlet in the housing.

The depth of the concave rotor portion is defined by a radially inwardly extending lip at the open end of the rotor. When sludge has accumulated in the compartments to a depth substantially equal to the depth of the concave portion, and suflicient to raise the bosses that surround the openings in the boot disposed on the radially inner sides of the compartments to a distance radially equal to the radially inwardly extending lip at the open end of the rotor, the clean fluid flowing out of the compartments flows across the lip. A pressure responsive switch is located at a position adjacent the lip for actuaice tion by fluid flowing across the lip. On actuation of the switch, the rotor speed is reduced sufficiently to allow the boot to return to its initial position in which it extends across, rather than into, the concave rotor portion. This results in contraction of the boot compartments so as to expel the sludge therefrom. The boot has separable inner and outer walls through which the sludge can flow, and vanes on the rotor provide for pumping of this sludge through an outlet opening in the housing.

The bosses that surround the passages which extend through the boot and the bosses that surround the openings in the boot disposed on the radially inner sides of the compartments effect a balance on the rotating boot and rotor assembly by lowering the column of incoming contaminated fluid in the quadrant of the rotor and boot assembly which is moved into the longest radius of rotation about the center axis by a condition of unbalance. The resilient material of which the boot is constructed permits the additional centrifugal force affect on the heavy quadrant to lower the height of the bosses and thereby reduce the fluid in the heavy quadrant and the resultant weight. The bosses that surround the passages which extend through the boot permit, in addition to the balancing effect, the clean fluid to flow over the radially inner surface of the boot thereby performing a secondary cleaning of the fluid to remove contaminates of less specific gravity than the fluid being cleaned.

The cover which surrounds and partially encloses the passages which extend through the boot forces the fluid, flowing over and contained by the radially inner surface of the boot to flow radially inwardly to escape over the bosses and through the passages into the surrounding rotor and housing. This flow of the fluid from the radially inner surface of the fluid layer to the radially inner surface of the boot and again to the radially inner surface of the bosses prevents the contaminates of less specific gravity than the fluid being cleaned from entering the passages through the boot. When the boot contracts to expel sludge from the compartments, on a reduction of speed, the light sediments are loosened from the radially inner surface of the boot, and these sediments along with the eflluent are thrown by centrifugal force from the radially inner surface of the boot into the sludge collecting compartment of the housing which surrounds the rotor, and is pumped out of the housing along with the sludge expelled from the compartments.

Further objects, features and advantages of this 111- vention will become apparent from a consideration of the following description, the appended claims, and the accompanying drawing in which:

FIGURE 1 is an elevational view of the centrifuge apparatus of this invention, with some parts broken away and other parts shown in section for the purpose of clarity;

FIGURE 2 is an elevational view of the flexible boot in the centrifuge apparatus of this invention, as viewed from the open end of the boot; and

FIGURES 3, 4 and 5 are transversesectional views of the boot as seen from substantially the lines 3-3, 4-4, and 5--5, respectively, in FIG. 2, with the covers for the discharge openings being omitted in FIG. 3 for purposes of clarity; and

FIGURE 6 is an enlarged view, partly in section, showing the assembly of a cover with the boot.

With reference to the drawing, the centrifuge apparatus of this invention, indicated generally at 10, is shown in FIG. 1 as consisting generally of a housing 12 provided with an inlet pipe 14 for fluid to be centrifuged, an outlet 16 for fluid which has been cleaned in the apparatus 10, and an outlet 13 for sludge and other foreign material removed from the fluid in the apparatus 10. An electric motor 20 having a drive shaft 22 is mounted on the housing 12 for driving a rotor shaft 24 which is rotatably mounted on the housing 12. Meshing gears 26 and 28 on the motor drive shaft 22 and the rotor shaft 24 provide for driving of the shaft 24 by the motor 20. An open-ended rotor 30, of irregular configuration, is mounted on the shaft 24 for rotation about the axis 32 thereof. The rotor 30 has a cone-shaped axial portion 34 having an outer surface 36 which is inclined upwardly and outwardly with respect to the shaft axis 32.

The rotor 30 also has a radially inwardly concave portion 38 which is disposed radially outwardly of the axial portion 34. The concave rotor portion 38 has an inwardly facing concave surface 40 which extends continuously about the axis 32 and communicates with the surface 36. The open end of the rotor 30 is defined by a radially inwardly extending lip 42 which is disposed a predetermined distance radially inwardly of the deepest part of the surface 40. This distance defines the depth of the concave portion 38. The rotor 30 also includes a passage defining portion 44 which cooperates with the surface 36 to provide inlet passages 46 for fluid and also forms radially outwardly extending impeller vanes 48 for a purpose to appear presently.

A flexible boot 50, formed of rubber or an equivalent material, is mounted on the rotor 30. The boot 50 is of generally continuous annular shape and is best illustrated in FIGS. 25, inclusive. The boot 50 has an inner portion 52 which is positioned against the rotor surface 36 and is retained thereon by a retaining ring 54. A flange 56 on the portion 52 is positioned against the rotor portion 44 and is secured thereto by a retaining ring 58. The boot 50 also includes an outer portion 60 which, when the rotor 30 is at rest, extends across the concave rotor portion 38, as shown in broken lines in FIG. 1, and terminates in a flange 62 which is disposed against the outer side of the lip 42 and is retained thereon by a retaining ring 64.

As shown in FIGS. 2 and 4, the boot 50 is formed with four longitudinally extending ribs 66 which divide the interior of the boot into four compartments 68, only one of which is shown in FIGS. 3 and 5, with the compartments being spaced circumferentially about the axis 32. As shown in FIG. 5, each compartment 68 is defined by radially inner and outer walls 70 and 72 with the walls 70 and 72 being spaced apart at the flange 56 to provide an inlet passage 74 for fluid entering the boot 50 in a manner to be explained in greater detail hereinafter.

Each compartment 68 is also provided with an outlet passage 76 which extends through the inner wall 70 and is formed in a boss 78 in the wall 70. Thus, fluid in a compartment 68 can flow through the passage 76 to a position on the radially inner side of the concave rotor portion 38. In each compartment 68, the walls 70 and 72 are integral in a very restricted area formed by a boss indicated at 80 in FIG. 3. A discharge opening 82 is formed in each boss 80 for providing fluid communication between the radially inner and outer sides of the boot portion 60. A cup-shape cover 108, as shown in FIG. 6, having elongated openings 102 spaced around the circumference, is fitted over each boss 80 in which a discharge opening 82 is formed. Each cover 108 has an integral axial stem 110 which extends through the corresponding opening 82 and carries a stop disc 112 which maintains the cover 108 in a loosely mounted position on the boss 80. The inner and outer walls 70 and 72 are also separated at the open end of the boot 50 which normally rests on the lip 42. The wall 70 is movable away from the wall 72 at the lip 42 only when the boot contracts to expel sludge.

In the operation of the centrifuge apparatus 10, assume that fluid to be centrifuged is being supplied to the inlet pipe 14. The motor 20 is operated so as to initiate acceleration of the rotor 30. Fluid from the inlet pipe 14 is directed upwardly through a housing passage 86 onto the rotor surface 36. The rotating cone-shaped rotor portion 34 provides for movement of the fluid upwardly along the rotor surface 36 from which the fluid travels into the inlet passages 74 for the boot compartments 68. As the compartments 68 in the boot 50 receive fluid, the fluid is passed through the compartments and is recirculated through the compartments 68 or pumped out of the apparatus until the necessary centrifugal force is applied to the boot 50 to remove sediments for which the apparatus is designed. When this desired centrifugal force is applied to the boot 50, the boot portion 60 flexes into the concave rotor portion 38, to a position tight against the outer boot wall '72. The lighter fluid particles are forced out of the compartments 68 through the passages 76. This fluid then flows over the inner surface 106 of the boot 50, passes through the openings 102 of the cover surrounding the boss 80, flows over the boss and is then thrown outwardly by centrifugal force through the discharge openings 82. Thus, fluid cleaned of heavy sediments continually fiows from the compartments 68 through passages 76, to the inner surface 106 where the light sediments are removed by a reversal of flow under the cover 108, over the bosses 80, and through the openings 82 which are aligned with openings 88 in the rotor portion 38. As shown in FIG. 1, the housing 12 includes a wall 90 which intercepts this fluid flowing radially outwardly through the openings 88. The outlet passage 16 is formed in the wall 90 so that the cleaned fluid ultimately flows out of the apparatus 10 through the passage 16.

The heavier particles, or sludge, continues to accumulate on the wall '72 in each compartment 68 causing the wall 70 for each compartment 68 to flex in a direction toward the axis 32 of rotation. In other words, each compartment 68 is expanded by the sludge accumulating therein. When the sludge has accumulated to a depth corresponding substantially to the depth of the concave rotor portion 38 so that the bosses 78 project radially inwardly beyond the lip 42, some of the fluid from the passages 7 6 will flow across the lip 42 rather than through the openings 82. This fluid will impinge on a diaphragm 92 (FIG. 1) mounted in the housing 12 at a position adjacent the lip 42. The diaphragm 92 forms a part of a conventional pressure responsive switch apparatus 94 which is connected in a conventional manner to the motor 20 so as to provide for a reduction in the motor speed when there is pressure on diaphragm 92. This results in a reduction in the speed of rotation of the rotor 30 suflicient to reduce the centrifugal forces on the boot 50 to the point where the boot, by virtue of its inherent flexibility will tend to return to its broken line position shown in FIG. 1. This causes the boot chambers 68 to contract, thereby forcing the sludge therein outwardly through the passages 76 and between the boot walls 70 and 72. This contraction of the boot 50 also loosens the light sedi ments which adhere to the inner surface 106 of the boot 50. These sediments are thrown off the surface 106 of the boot 50 by centrifugal force.

The motor 20 is then again operated by the switch apparatus 94, since the pressure on the diaphragm 92 is relieved, to increase the speed of the rotor 30 and cause the vanes 48 to pump the sludge out of the housing 12 through the outlet opening 18. A gasket 98 in the housing 12 prevents flow of sludge into the clean fluid outlet 16. The resumption of the rotation of the rotor 30 at a speed suflicient to move the boot portion 60 into the concave rotor portion 38 provides for a resumption of the above described cycle which is thus continuously repeated to provide for a continuous operation of the centrifuge apparatus 10 to clean the fluid supplied thereto. When a condition of unbalance in the rotor 30 and boot 50 assembly exists, the assembly is thrown from a true axis of rotation to an elliptical axis. The increased radius of rotation in one quadrant of the assembly results in greater centrifugal force on the quadrant of the assembly having the increased radius of rotation. As this condition occurs, the resilient bosses 78 and 80 on the inner surface .106 of the boot 50, are compressed to a greater extent in the quadrant of the assembly having the increased radius of rotation, thereby reducing the column of fluid contained in the passages 74 of boot 50, and on the inner surface 106 of the boot 50. This reduction of fluid offsets the unbalancing weight of the rotor-boot assembly and reduces the resulting vibration of the apparatus.

From the above description it is seen that the invention produces improved centrifuge apparatus in which the rotating flexible boot 50 expands and contracts so as to clean itself automatically of sludge, provides a barrier against the pumping of contaminated fluid into the area of clean fluid, and compensates for an unbalanced condition in the rotor and boot 50 assembly.

What is claimed is:

1. Centrifuge apparatus for fluid comprising:

a rotor having an axis of rotation and having a radially inwardly concave portion extending about said axis;

a flexible boot mounted on said rotor and extended across said portion when said rotor is at rest, said boot having flexible compartments and being movable by centrifugal force into said concave rotor portion during rotation of said rotor;

inlet means in said boot for directing fluid into said compartments so as to expand said compartments radially inwardly toward said axis;

passage means in said boot communicating said com-- partments with the radially inward surface of said boot to provide outlets for lighter material in said compartments; and

means forming discharge openings extending through said rotor and said boot communicating the radially inner surface of said boot with the radially outer surface of said rotor;

said boot, on discontinuance of said rotor rotation, being sufliciently flexible to return to said position extending across said rotor portion so as to contract said expanded compartments and expel heavier material therein.

2. Centrifuge apparatus according to claim 1 wherein said rotor has an axial portion disposed radially inwardly of and spaced from said concave portion, and means for directing fluid to be centrifuged to said axial portion for subsequent flow under the action of centrifugal force outwardly toward said concave portion.

3. Centrifuge apparatus according to claim 2 wherein said boot includes a radially inner portion mounted on said axial rotor portion, said radially inner boot portion being formed with said inlet means.

4. Centrifuge apparatus according to claim 3 wherein said axial rotor portion is cone-shape, and said boot is of an annular continuous shape extending completely about said axial rotor portion.

5. Centrifuge apparatus according to claim 4 wherein a plurality of said boot compartments are provided and arranged in a circumferentially spaced relation about said axial cone portion and wherein each of said compartments is provided with one of said passage means and one of said discharge openings, said one passage means and said one discharge opening being spaced apart in a direction circumferentially of said axial cone portion.

6. Centrifuge apparatus according to claim 1 wherein said rotor concave portion has a continuous circular lip at the axially outer end thereof and a concave surface which extends a predetermined distance outwardly from said lip in a direction radially of said axis and wherein said boot compartments are formed by radially spaced inner and outer walls which extend across said lip, said walls being separable adjacent said lip.

7. Centrifuge apparatus according to claim 6 further including motor means arranged in a drive relation with said rotor for rotating said rotor about said axis, and motor control switch means disposed adjacent said lip for actuation by material flowing across said lip.

8. Centrifuge apparatus according to claim 1 further including a housing enclosing said rotor and said boot, means on said housing for directing sludge containing fluid to be cleaned to said inlet means in said boot, outlet means on said housing for sludge, and vanes on said rotor for moving sludge in said housing out said outlet means.

9 Centrifuge apparatus according to claim 8 wherein said housing has an annular wall extending about said rotor and positioned to intercept fluid flowing through said discharge openings, and an outlet opening for fluid in said annular wall spaced from said outlet means.

10. Centrifuge apparatus according to claim 9 further including means in said housing forming a partition extending about said rotor and located between said outlet means for sludge and said outlet opening for fluid.

References Cited UNITED STATES PATENTS 3,244,363 4/1966 Hein 233-28 3,297,244 1/1967 Hein 233-27 WILLIAM I. PRICE, Primary Examiner U.S.Cl.X.R. 233--19 

